Escapement mechanism for typewriters



Dec. 19, 1967 0, KRAUSS ET AL 3,358,806

ESCAPEMENT MECHANISM FOR TYPEWRTERS I Filed Feb. 24, 1964 l 4 sheets-sheet 1 Filed Feb. 24, 1964 Dec. 19, 1967 o, MUSS ET AL 3,358,806

ESCAPEMENT MECHNISM FOR TYPEWRITERS 4 Sheets-Sheet 2 Ms *I [t TS /0 INVENTORS (9H-1J crauyg Dec. 19, 1967 Q KRAUSS ET Al.

ESCAPEMENT MECHANISM Foa TYPEWRITERS 4 Sheets-Sheet 3 Filed Feb. 24, 1964 Dec. 19,1967 o. KRAUSS ET Al- 3,353,806

ESCAPEMENT MECHANISM FOR TYPWRITERS Filed Feb. 24, 1964 4 Sheets-Sheet 4 United States Patent O ESCAPEMENT MECHANISM FOR TYPEWRITERS Otto Krauss, Herbert Decker, and Manfred Link, Nurnberg, and Walter Stuiber, Stein, near Numberg, Germany, assignors to Triumph Werke Nrnberg A.G.,

Numberg, Germany Filed Feb. 24, 1964, Ser. No. 346,716 Claims priority, application Germany, Feb. 27, 1963, G 37,157/63 5 Claims. (Cl. 197-84) The present invention relates to an escapement mechanism for a typewriter or similar business machine including a stepwise movable carriage.

Escapement mechanism of this type must be constructed lin such a manner that the carriage moves rapidly one step after each type bar actuation, and is also very rapidly stopped without a bouncing movement. Such bouncing movement upon engagement between the carriage rack and the escapement pawl may cause the printing of characters in displaced positions so that the appearance of the typewritten script is inferior.

Escapement mechanism is known in which the escapement pawl is moved in a direction opposite to the carriage movement to engage the carriage rack before the carriage has completed one step. Escapement pawls of this type are mounted for turning and translatory movement on pins passing through elongated slots in the escapement pawl. However, this type of mounting does not permit a precise positioning of the escapement pawl, and the pawl is also subjected to very great wear.

The escapement mechanism must have a very rigid construction, since the'rapidly moving carriage must be stopped quickly in spite yof its great inertia. In order to stop the carriage faster after a step, and to reduce the impact on the escapement pawl, -it has been proposed to provide resilient means in the escapement mechanism. Such resilient means reduce the hard impact of the carriage on the escapement pawl, but it can be used for a limited time only since due to the heavy wear, the dampening characteristics are lost.

It is one object of the invent-ion to overcome the disadvantages of known escapement mechanisms for typewriter carriages, and to provide an escapement mechanism which operates rapidly, dampens the impact of the carriage, has a strong mechanical construction assuring a long time of undisturbed use, and reduces the noise created by the impact of the carriage rack on the escapement pawl.

Another object of the invention is to provide an escapement mechanism comprising two connected members movable in transverse directions so that the escapement pawl need not be mounted for movement intwo directions.

Another object of the invention is to damp the carriage movement by non-resilient damping means which consume the energy of the inertia of the moving carriage before the same is stopped by the escapement mechanism.

Another object of the invention is to provide an escapement mechanism which produces very little noise.

Another object of the invention is to provide an escapement mechanism which operates so rapidly that the type actions can be operated in very rapid succession.

Another object of the present invention is to provide an escapement mechanism which can be set to automatic double spacing.

Another object of the invention is to provide an escapement mechanism which is rendered inoperative during operation of the back spacing device or of the tabulating device of a typewriter.

With these objects in view, the present invention provides an escapement mechanism for the carriage of a Patented Dec. 19, 1967 typewriter. One embodiment of the invention comprises a support reciprocable along the rack of the carriage; an escapement member mounted on the support for movement between a rack engaging position and a releasing position, and for movement with the support between a plurality of positions cooperating with different teeth of the rack. Biasing means urge the support to move opposite to the direction of carriage movement, and urge the escapement member to move to the position engaging the rack of the carriage. When the operator actuates operating means, the escapement member is moved to the releasing position, and the support moves with the escapement member opposite to the direction of carriage movement whereupon the escapement member engages the rack of the carriage before the same starts its stepwise movement. When the carriage then moves, the escapement member and the support move together with the carriage until the support of the escapement member engages a stop which brings the support with the escapement member, and the carriage to a standstill.

Control stop means are provided for limiting movement of the support in the opposite direction, and such control stop means can be set to two different positions so that the escapement member moves either one step or two steps opposite to the direction of the carriage movement, and then moves with the carriage corresponding distances so that by adjustment of the control stop means the mechanism can be set to a condition in which the carriage performs single steps, and another condition in which the carriage performs double steps, as is desirable for typing spaced letters.

In accordance with the invention, damping means are provided for reducing the speed of the carriage before the same is stopped. Such damping means are preferably pneumatic means which consume the energy of the inertia of the carriage by transforming the kinetic energy into heat.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to -its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specilic embodiments when read in connection with the accompanying drawings, in which:

FIGS. 1 to 6 are fragmentary side views of an escapement mechanism according to the invention and illustrating different operational positions of the mechanism;

FIG. 7 is a fragmentary perspective View of a part of the mechanism; and

FIG. 8 is a` fragmentary perspective View illustrating the connection between spacing device with the escapement mechanism.

Referring now to the drawings, a rack 1 having teeth and recesses I, II, III between the teeth is secured to the carriage of a typewriter. FIG. 1 shows the normal inoperative position of the escapement mechanism in which the projection 3 of an escapement pawl 2 engages recess I of the rack, and abuts the next following tooth of the rack since the carriage is biased to move in the direction of the arrow a by the conventional carriage spring 1a with which it is connected by a band 1b. A support lever 5 is mounted on the machine on a stationary pivot pin means 6 and has a portion provided with an abutment face 7, and with a pivot pin 4 on which escapement pawl 2 is mounted for angular movement between the rack engaging position illustrated in FIG. 1, and the releasing position illustrated in FIG. 2.

When the pressure of the carriage spring presses escapement pawl 2 and the upper portion of lever 5 in the direction of the arrow a, abutment face 7 abuts a terminal stop 8 secured to the frame of the machine, and

a tabulating device and a back consequently movement of the carriage is prevent. Support lever has an arm 10 articulated to a link 11 which is connected to a damping means in the form of a pneumatic brake 11a.

A spring 12 is connected at one end to escapement pawl 2, and at the other end to a pin 13 fixed to the stationary frame of the machine. Spring 12 is oriented at an angle to the direction of carriage movement so that the spring force urges escapement pawl 2 to turn in counterclockwise direction from the releasing position shown in FIG. 2 to the engaging position shown in FIG. 1. At the same time, a force is exerted by spring 12 on the upper portion of support lever S and urges the same to turn in clockwise direction away from stop 8. Such movement, however, is prevented due to the fact that the carriage spring acts with a far greater force on escapement pawl 2 than spring 12.

Escapement pawl 2 has a projecting part 14 with a face parallel to rack 1 in the position of FIG. 1. A recess 15 is separated by shoulder 15a from this face, and is located adjacent the projection 3 of escapement pawl 2.

A control stop lever 22, best seen in FIG. 7, is mounted on a stationary bracket 19a of the frame for turning movement about a pivot screw 19 located in a slot 1917 of bracket 19a. As best seen in FIG. 7, control stop lever 22 has two stepped abutment faces 20 and 21 which are respectively positioned opposite a projection 9 of support lever 5 when control stop lever 22 is turned about pivot 19.

Control stop lever 22 has a portion 24 to which a rod is secured which is composed of a rod portion 29, a threaded connecting part 28, and a guide rod 25 which extends substantially parallel to the rack 1. The hub 27 of an operating lever 16 is mounted on rod 25 for turning and axial movement. An abutment 25a is secured to rod 25, and supports a spring 26 coiled about rod 25 and abutting hub 27 so that the operating lever 16 is urged outwardly until abutting a stop 25h.

As best seen in FIG. S, operating lever 16 is connected to a link 18 which is operated by the universal bar 18a of the typewriter whenever a typebar 18h or the space bar is operated for the purpose of causing the carriage to move a step.

Arm 17 of operating lever 16 abuts portion 14 of escapement pawl 2, and when operating lever 16 is actuated, pawl 2 is turned in clockwise direction from the position shown in FIG. l to the position shown in FIG. 2 while arm 17 moves in the direction of the arrow b in FIG. 8. The exact position of arm 17 on the horizontal face of projection 14 can be adjusted by operation of the threaded connection 28 which permits the displacement ot rod 25 with hub 27 of operating member 16, 17.

Blocking means are provided for controlling the escapement mechanism during operation of the tabulator and back spacing key of the typewriter, and include a springloaded blocking lever 30, a connecting shaft 32 mounted in the frame of the machine, and another arm 33, as best seen in FIG. 8. A link 38 is connected to lever arm 33, and to the back spacing key, not shown, of the typewriter so that blocking lever 30 is held in a blocking position engaging arm of support lever 5 by a blocking face 31.

Arm 33 abuts a shiftable member 34 which includes a guide member 36 provided with slots in which stop tabs 35 of the tabulating device of the typewriter are mounted for vertical sliding movement. Each stop tab 35 can be operated to be set to an operative position in which its upper end projects beyond the top of guide member 36, as shown for one stop tab 35 in FIG. 8. Member 34, 36 is mounted on the stationary frame of the typewriter, and each set tabulator stop tab 35 cooperates with a stop 37 on the carriage of the typewriter to stop the carriage in a position determined by the setting of the respective stop tab 35. This arrangement is known, and not an object of the invention. Member 34 has a pair ot longitudinal slots 34a receiving guide pin 34h, so that member 34, 36 can move a short distance when the carriage stop 37 engages a set tabulator tab 35. Such movement of member 34 will cause turning movement of lever arm 33 to the position illustrated in FIG. 8 in which blocking lever 30 is turned to a position abutting support lever 5 when the same is in the position shown in FIGS. 1 and 2.

The escapement mechanism illustrated in FIGS. 1 to 8 operates as follows:

Single step carriage movement In the normal condition of the typewriter, the escapement mechanism is in the position shown in FIG. l. The projection 3 of escapernent pawl 2 projects into a recess I of rack 1 of the paper carriage of the typewriter, and holds the carriage which is urged to move in the direction of the arrow a by the conventional carriage spring, not shown. Spring 12 acts on escapement pawl 2 with a force component which tends to turn escapement pawl 2 in counterlockiwse direction and to push projection 3 of escapement pawl 2 into recess I in the position illustrated in FIG. l. The force of spring 12 acts parallel to rack 1 and tends to turn support lever 5 in clockwise direction, but since the carriage spring exerts a stronger force in the opposite direction, spring 12 is ineffective and the abutment face 7 of support lever 5 abuts the terminal stop 8.

Control stop lever 22 is in a position in which its abutment face 20 is located opposite projection 9 of support lever 5 spaced from the same.

When a typewriter key, not shown, is operated, link 1S acts on operating lever 16 to turn the same in the direction of the arrow b in FIG. 8 so that arm 17 moves downward as viewed in FIGS. 1 and 2 and engages projection 14 of escapement pawl 2 to turn the same in clockwise direction from the position shown in FIG. 1 to the position shown in FIG. 2. When projection 3l moves out of recess I of rack 1 and assumes the releasing position shown in FIG. 2, the carriage is free to move in the direction of the arrow a under the action of the carriage spring 1a.

Before the carriage starts such movement, and as soon as the tip of projection 3 has lett recess I, the pull of spring 12 turns support lever 5 in clockwise direction to the position shown in FIG. 3, and since escapement pawl 2 is mounted on support lever 5, escapement pawl 2 is shifted in the direction of the arrow c opposite to the direction of carriage movement until projection 9 abuts the abutment face 20 of control stop lever 22 in the position of FIG. 3. Projection 3 has thus been shifted at high speed in a direction opposite to the carriage movement and is located opposite the next following recess II of rack 1 before the carriage and rack 1 have moved in the direction of the arrow a which is due to the fact that the inertia of the carriage is much greater than the inertia of the light parts 5 and 2. During the turning movement of support lever 5 and the movement of escapement pawl 2 to the right in the direction of the arrow c, recess 15 of escapement pawl 2 has also moved to the right, and in the position of FIG. 3, arm 17 ot operating lever 16 is located opposite recess 15. The turning movement of escapement pawl 2 out of a recess of rack 1 was accomplished by the force of lever arm 17 acting on projection 14, and as soon as lever arm 17 is located opposite recess 15, spring 12 can turn escapement pawl 2 in counterclockwise direction from the position shown in FIG. 3 to the position shown in FIG. 4 in which the tip of projection 3 is located in recess II of rack bar 1, whose next following tooth immediately engages projection 3 so that the force of the carriage spring is transmitted through the escapement pawl to the upper portion ot support lever 5 whereby support lever 5 is turned in counterclockwise direction to the position shown in FIG. 1 in which stop 8 engaging abutment face 7 blocks further movement of support lever 5 and of the carriage.

In the above description of the operation, it has been assumed that arm 17 remains in its turned actuated position so that recess is necessary for permitting the return movement of escapement pawl 2 to its rack engaging position. Actually, however, during normal operation of the typewriter, operating lever 16 and arm 17 immediately return to the normal position shown in FIG. 1 so that lever arm 17 is located farther from recess 15 in the position of escapement pawl 2 shown in FIG. 3, and just outside of recess 15 in the position of FIG. 4. During the normal operation of the typewriter, recess 15 would not be necessary, but in the event that type bars are jammed and cannot return to their normal positions, operating lever 16 is also jammed and remains in the actuated position shown in FIGS. 2, 3 and 4, and consequently escapement pawl 2 could not turn from the position shown in FIG. 3 to the position shown in FIG. 4 if no recess 15 were provided.

If lever arm 17 of operating lever 16 remains in the actuated position shown in FIG. 4 due to the jamming of type bars, shoulder 15a of recess 5 engages lever arm 17 when escapement pawl 2 and support lever 5 are moved in the direction of the arrow a by the carriage and carriage spring toward stop 8. Since operating lever 16, 17 is mounted on rod 25 for axial movement, spring 26 is slightly compressed while operating member 16 is moved to the left on rod 25. As soon as the jammed type bars are restored to normal positions, spring means 116, see FIG. 8, and acting in a conventional manner on operating member 16, turn operating member 16 back to the normal position shown in FIG. l, overcoming the small friction produced by spring 26 between lever arm 17 and shoulder 15a. Consequently, even if the type bars are jammed, jamming of the escapement pawl 2 and corresponding running away of the carriage in the direction of the arrow a is prevented by the recess 15.

Doube-spacng operation In typing of headings it is customary to provide double spaces between successive letters. This is normally accomplished by operating the space bar after the carriage has performed a single step under the control of the escapement mechanism. In accordance with the present invention, the escapement mechanism is set to automatically produce double spaces after each key actuation, in other words to stop the carriage after the same has moved a distance corresponding to two normal steps of the carriage.

As explained above, during the normal single step operation of the escapement mechanism, abutment face 20 of control stop lever 22 is effective to stop support lever 5 in the position of FIG. 4. When the carriage is to perform double steps, a control means including a manually operated member 23a, see FIG. 1, and link 23 is manually set on the typewriter to shift link 23 so that control stop lever 22 is turned from its normal position in which abutment face 20 is located opposite projection 9, to a double step position in which abutment face 21 is located opposite projection 9. Link 23 is attached to projecting part 24 of stop lever 22 to which rod 25 and operating lever 16 are also connected. Consequently, operating lever 16 is shifted to the right out of its normal position shown in FIG. l, and is located spaced a greater distance from recess 15 and shoulder 15a when abutment face 21 cooperates with support lever 5.

When a key is operated in this condition of the escapement mechanism, link 18 turns operating lever 16 as explained above so that escapement pawl 2 is turned in clockwise direction until projection 3 releases recess I, whereupon spring 12 turns support lever 5 in clockwise direction to the position shown in FIG. 5 in which projection 9 abuts abutment face 21 of control stop lever 22. `It is evident that support lever 5 can turn through a greater angle as compared with the operation described with reference to FIGS. 1 and 2, and consequently escapement pawl 2 is shifted to the right as viewed in FIG. 5 to a position located opposite recess III, instead of re- 'the normal operation.

Since rod 25 with operating lever 16 was shifted when control stop lever 22 was set to the double step operation, lever arm 17 was spaced twice the distance from recess 15 than in the condition of FIG. 1, and consequently will be located opposite recess 15 in the position shown in F-IG. 5 in Which escapement pawl 2 has travelled to the right twice the distance as during the normal operation. Consequently, even if the type bars are jammed, and operating lever 16 cannot return to its normal position, recess 15 will permit escapement pawl 2 to return to the rack engaging position shown in FIG. 6. Shoulder 15a again engages lever arm 17 during movement of escapement pawl 2 to the left while the carriage moves a distance corresponding to two steps until stopped by terminal stop 8. When operating lever 16 is urged to the left as viewed in FIG. 6, coil spring 26 is compressed so that operating lever 16 is again moved to the right to its normal position when releasing shoulder 15a. If coil spring 26 is secured to hub 27, and torsionally stressed by operating lever 16 in the position shown in FIGS. 3 to 6, it also exerts a torque on operating lever 16 tending to return the same to its normal position.

The connection between rod 25 and control stop lever 22 renders recess 15 effective during double step operations of the escapement mechanism.

In the above described operations of the escapement mechanism, the escapement pawl is moved in a direction opposite to the carriage movement to engage the rack of the carriage before the released carriage has started its movement under the action of the carriage spring. This arrangement has advantages over constructions in which the carriage is stopped by the escapement pawl when the same moves back into a rack engaging position. However, during tabulating operations, and back spacing operations, such relative movement between escapement pawl and the carriage rack are undesirable since the carriage would not be stopped in the intended position.

Tabulating and back spacing operations During tabulating and back spacing operations, the escapement pawl 2 must be moved to a position releasing the rack of the carriage, but support lever 5 must not be shifted opposite to the direction of carriage movement with escapement pawl 2.

Blocking means 33, 32, 30 is normally held by a spring 30a in a position in which abutment face 31 of blocking lever 31) is spaced from support lever 5 in the normal position of FIG. l. Blocking means 33, 32, 30 can be moved to a blocking position in which abutment face 31 abuts arm 10 of support lever 5, as shown in FIG. 8.

Blocking means 33, 32, 30 can be moved from its normal inoperative position to the blocking position by a link 38 which is operated by back spacing means including link 38. Upon operation of the back spacing key, not shown, link 38 is shifted to the left as viewed in FIG. 8, and turns the blocking means so that blocking lever 30 moves to the block-ing position in which turning of support lever 5 in clockwise direction is prevented. Consequently, when operating lever 16 is turned in the direction of the arrow b in FIG. 8, and escapement pawl 2 is turned in clockwise direction to the position shown in F-IG. 2, blocking lever 30 prevents turning of support lever 5 in clockwise direction out of the position shown in FIG. 2 so that escapement pawl 2 cannot move to the position shown in FIG. 3 in the direction of the arrow c. Consequently, spring 12 will turn escapement pawl 2 about pivot pin 4 in counterclockwise direction so that projection 3 would move back to the same recess as before, were it not for the fact that the conventional hook of the back spacing means has engaged a recess in rack 1 under the control of the conventional back spacing key and shifted the carriage in the meantime one step in the direction of the arrow c so that projection 3 will fall into the preceding recess, as desired.

When the tabulating means 90 of the typewriter is actuated, escapement pawl 2 is turned about pin 4 by a part 90a of the tabulator means to the position of FIG. 2 so that the carriage can start its tabulating movement which continues as long as tabulator key 90 is depressed. Release of key 90 causes engagement of rack 1 by projection 3. When key 90 is held depressed and the carriage arrives in a tabulating position in which a tabulator tab 35 was set, tabulator stop 37 of the carriage abuts the projecting set tabulator tab 35, and shifts member 36, 34 to the left as viewed in FIG. 8 from a position in which pins 34b are located at the left ends of slots 34a to the illustrated position in which pins 34h are located at the other end of slots 34a and stop member 34, 36 and thereby the carriage.

During such movement, lever arm 33 of the blocking means is turned so that blocking lever 30 is turned from its normal inoperative position to the blocking position shown in FIG. 8. End face 31 of blocking lever 30 engages arm of lever 5 and turns the same to the position shown in FIG. l before projection 3 of pawl 2 can engage a recess in the rack. In this position turning move- -ment of support lever S in clockwise direction is prevented and projection 3 engages a recess of the rack when tabulator key 90 is released. A lost-motion connection between link 3S and the back spacing key, not shown, permits the turning of lever arm 33 with link 38. The movement of member 34, 36 is used in known tabulator constructions for releasing the locked tabulator tab 35 so that the same can return to its normal position releassing tabulator stop 37. The U.S. Patents 1,090,219 and 3,095,077 disclose tyewriter constructions of the type improved by the present invention.

Due to the fact that support lever 5 is blocked by blocking lever 30, escapement pawl 2 does not perform a movement in the direction of the arrow c, and its projection 3 will be urged by spring 12 to engage a recess spaced from the previously engaged recess I a distance corresponding exactly to the tabulated distance.

Damping of the carriage movement Support lever 5 operates through link 11 the damping air brake 11a so that every time support lever 5 is turned from the positions shown in FIG. 3 or 5 to the position shown in FIG. l, the damping air brake is actuated. Since escapement pawl 2 connects support lever 5 with rack 1 and the carriage during such movement in the direction of the arrow a, the carriage is braked by the damping means 11a. The pneumatic braking of the carriage prevents a bouncing back of the carriage when abutment face 7 engages stop 8. It is necessary to make abutment face 7, and the corresponding abutment face of stop 8 of hard metal in order to exactly determine the length of the carriage steps. A spring 11b urges the piston 11C of damping means 11a into the position shown in FIG. 3. The force of spring 12 is not required for this operation during clockwise movement of support lever 5 when the same moves away from ange 11d. The fast pneumatic braking movement caused by the inertia of the carriage requires far more force than the compression of spring 11b. The damping piston 11C is returned by spring 11 from the position of FIG. l to the position of FIG. 3 until ange 11d abuts against lever 5.

In accordance with the .present invention, the movement of supp-ort lever 5 is dampened at least during the last part of its movement toward stop 8 so that the speed of the carriage is gradually reduced. Tests and exact measurings have proven that the braking of the carriage by damping means requires less time than the destruction of the kinetic energy after an undampened impact of abutment face 7 on stop S. When the typewriter keys are operated in rapid succession, fast stopping of the carriage after a step has the result that the next following imprint is made in exactly the right position so that the typed characters are exactly spaced. Due to the damping of the carriage before engagement with the stop, no bouncing back of the carriage takes place after engagement between abutment face 7 and stop 8. In order to achieve this result, the damping means are in accordance with the present invention non-resilient, and consume the entire kinetic energy of the carriage, for example by trasforming the energy into heat, so that after the carriage has been stopped, no energy remains which could cause bouncing back of the carriage.

Adjustments In order to exactly determine the position of the carriage, stop 8 is adjustable, for example by threaded means 8a located in the slot 8b of a iixed -bracket 8c so that the carriage position in the normal condition of the escapement mechanism shown in FIG. l is exactly determined. In this manner, the left end position of projection 3 is set. The right end position of projection 3 of escapement pawl 2 is determined by adjusting control stop lever 22 in vertical direction by adjustment of screw 19 relative to bracket 19a whereby the abutment faces 20 and 2l of control lever 22 are moved toward or away from projection 9 of support lever 5.

The exact position of operating lever arm 17 on projection 14 relative to recess 15 is adjusted by operating the threaded means 28 by which the length of member 29, 2S, 25 can be varied. No other adjustments are required.

From the above description of a preferred embodiment, it will become apparent that the escapement mechanism of the present invention comprises few and simple parts which operate reliably in such a manner as to be subjected to very little wear. The principle of the invention may also be applied to escapement mechanism employing two escapement pawls in which event each escapement pawl is mounted on an individual support lever 5, each of which is connected to a damping means.

It will be understood that each of the elements described above, or two or more together, may also ind a useful application in other types of escapement mechanisms differing from the type described above.

While the invention has been illustrated and described as embodied in an escapement mechanism in which an escapement pawl is mounted for turning movement on a support lever which shifts the escapernent pawl opposite to the direction of the carriage movement, it is not intended to be limited to the details shown, since various modications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. An escapement mechanism comprising, in combination, carriage means biassed to move in one direction and having a rack with teeth spaced in said one direction; a support reciprocable along said rack; an escapement member mounted on said support for movement between a rack engaging position and a releasing position, and for movement with said support between a plurality of positions cooperating with different teeth of said rack, said escapement member having a lrecess; biassing means for urging said support to move opposite to said one direction of carriage movement for moving said escapement member to said plurality of positions, and said escapement member to move to said engaging position; operating means including an operating member movable transversely to said one direction of carriage movement to and from an operative position engaging said escapement member for moving said escapement member to said releasing position so that lsaid biassing means move said support with saidl escapement member in a direction opposite to the carriage movement until said escapement member moves to said engaging position whereupon said carriage means moves said escapement member and said support in said one direction, said operating member being located opposite said recess when said support has moved opposite to said one direction so that said ecapement member is free to move to said engaging position even if said operating member remains in said operative position, sad operating means including a means supporting said operating member for movement in said one direction, and resilient means opposing movement of said operating member whereby said operating member moves with said carriage means, said support, and said escapement member when located in said recess and engaged by said escapement member; and stop means for limiting movement of said support and said carriage means in said one direction.

2. An escapement mechanism comprising, in combination, carriage means biassed to move in one direction and having a rack with teeth spaced in said one direction; a support reciprocable along said rack; an escapement member mounted on said support for movement between a rack engaging position and a releasing position, and for movement with said support between a plurality of positions cooperating with diierent teeth of said rack, said escapement member having a recess; biassing means for urging said support to move opposite to said one direction of carriage movement for moving said escapement member to said plurality of positions, and said escapement member to move to said engaging position; operating means including an operating member movable transversely to said one direction of carriage movement to and from an operative position engaging said escapement member for moving said escapement member to said releasing position so that said biassing means move said support with said escapement member in a direction opposite to the carriage movement until said escapement member moves to said engaging position whereupon said carriage means moves said escapement member and said support in said one direction, said operating member being located opposite said recess when said support has moved opposite to said one direction so that said escapement member is free to move to said engaging position even if said operating member remains in said operative position, said operating means including a rod supporting said operating member for movement in said one direction, and resilient means opposing movement of said operating member whereby said operating member moves with said carriage means, said support, and said escapement member when located in said recess and engaged by said escapement member; first stop means for limiting movement of said support and said carriage in said one direction; and second stop means for limiting movement of said support in the opposite direction under the action of said biassing means, and being adjustable so that said escapement member moves in said opposite direction different distances for engaging different teeth of said rack whereby the length of carriage steps is adjusted, said second stop means being operatively connected with said rod for shifting said operating member relative to said escapement member and recess in accordance with the adjustment of said second stop means.

3. In a typewriter including a tabulating device, in

combination, an escapement mechanism comprising carriage means biassed to move in one direction and having a rack with teeth and recesses spaced in said one direction; a support reciprocable along said rack; an escapement member mounted on said support for movement between a rack engaging position and a releasing position, and for movement with said support between a plurality of positions cooperating with different teeth of said rack; means connecting said escapement member with said tabulating device so that said escapement member is moved to said releasing position when said tabulating device is operated; biassing means for urging said support to move opposite to said one direction of carriage movement, and said escapement member to move to said engaging position; operating means for moving said escapement member to said releasing position out of one said recesses so that said biassing means move said support with said escapement member in a direction opposite to said one direction until said escapement member moves to said engaging position into another recess before said carriage means moves, whereupon said carriage means moves said escapement member and said support in said one direction; stop means for limiting movement of said support and said carriage means in said one direction; and blocking means operable by said tabulating device to move to a blocking position when said tabulating device is operated, said blocking means moving said support in said one direction to its initial position and engaging in said blocking position said support for blocking movement of the same in said opposite direction under the action of said biassing means; and damping means connected to and operated by said support when the same is moved by said carriage means in said one direction so that said carriage means is braked while moving the distance between said one and said other recess.

4. In a typewriter, in combination, an escapement mechanism comprising carriage means biassed to move in one direction and having a rack with teeth and recesses spaced in said one direction; stationary pivot means; a support lever mounted on said stationary pivot means for turning movement about the same and having a portion reciprocable substantially in the direction of said rack; an escapement pawl mounted on said portion of said support lever for angular movement between a rack engaging position and a releasing position, and for movement with said portion between a plurality of positions located opposite different recesses of said rack said escapement pawl having a `face substantially parallel to said rack, and a recess in said face; spring means secured to said stationary pivot means and connected to said escapement pawl for turning the same into said engaging position and acting on said support lever through said escapement pawl to urge said portion to move opposite to said one direction of carriage movement for moving said escapement member to said plurality of positions; a rod extending parallel to said rack; an operating member mounted on said rod for movement with the same and for turning movement, said operating member having a part in sliding engagement with said face of said escapement pawl for turning the same from said engaging position to said releasing position so that said spring means moves said support lever with said escapement pawl in a direction opposite said one direction, said operating member being located opposite said recess of said escapement pawl when the same has been moved opposite to said one direction of carriage movement so that said escapement pawl is free to move to said engaging position even if said operating member remains in said operative position; control stop means mounted on said stationary pivot means for turning movement between two stop positions and having two stepped stop faces respectively cooperating with said support lever in said stop positions for stopping movement of said support lever when said escapement pawl has moved distances corresponding to the distance between two successive recesses,

in said one direction of carriage movement, said control stop means being Connected with said rod for shifting the same with said operating member parallel to said rack so that said part of said operating member moves relative to said recess and said face of said escapement pawl; and terminal stop means for limiting movement of said support lever and said carriage means in said one direction.

5. A mechanism as set forth in claim 4i wherein said operating member is mounted on said rod for moving along the same, and including a spring abutting said rod and said operating member so that said spring is deformed when said operating member moves on said rod while located in said recess of said escapement pawl and er1- gaged by the same during movement of the same with said carriage, said rod including two parts, and an adjustable part between said two parts whereby the position of said operating member can be adjusted.

References Cited UNITED STATES PATENTS 1,090,219 3/1914 Kurowski 197-64 2,010,223 8/ 1935 Gabrielson 197-183 X 2,536,619 1/ 1951 Yaeger 197-85 2,862,595 12/ 1958 Toggenburger 197-843 2,872,015 2/ 195 9 Toggenburger 197-91 3,095,077 `6/ 1963 Byers 197-97 ROBERT E. PULFREY, Primary Examiner.

E. T. WRIGHT, Assistant Examiner. 

1. AN ESCAPEMENT MECHANISM COMPRISING, IN COMBINATION, CARRIAGE MEANS BIASSED TO MOVE IN ONE DIRECTION AND HAVING A RACK WITH TEETH SPACED IN SAID ONE DIRECTION; A SUPPORT RECIPROCABLE ALONG SAID RACK; AN ESCAPEMENT MEMBER MOUNTED ON SAID SUPPORT FOR MOVEMENT BETWEEN A RACK ENGAGING POSITION AND A RELEASING POSITION, AND FOR MOVEMENT WITH SAID SUPPORT BETWEEN A PLURALITY OF POSITIONS COOPERATING WITH DIFFERENT TEETH OF SAID RACK, SAID ESCAPEMENT MEMBER HAVING A RECESS; BIASSING MEANS FOR URGING SAID SUPPORT TO MOVE OPPOSITE TO SAID ONE DIRECTION OF CARRIAGE MOVEMENT FOR MOVING SAID ESCAPEMENT MEMBER TO SAID PLURALITY OF POSITIONS, AND SAID ESCAPEMENT MEMBER TO MOVE TO SAID ENGAGING POSITIION; OPERATING MEANS INCLUDING AN OPERATING MEMBER MOVABLE TRANSVERSELY TO SAID ONE DIRECTION OF CARRIAGE MOVEMENT TO AND FROM AN OPERATIVE POSITION ENGAGING SAID ESCAPEMENT MEMBER FOR MOVING SAID ESCAPEMENT MEMBER TO SAID RELEASING POSITION SO THAT SAID BIASSING MEAND MOVE SAID SUPPORT WITH SAID ESCAPEMENT IN A DIRECTION OPPOSITE TO THE CARRIAGE MOVEMENT UNTIL SAID ESCAPEMENT MEMBER MOVES TO SAID ENGAGING POSITION WHEREUPON SAID CARRIAGE MEANS MOVES SAID ESCAPEMENT MEMBER AND SAID SUPPORTT IN SAID ONE DIRECTION, SAID OPERATING MEMBER BEING LOCATED OPPOSITE SAID RECESS WHEN SAID SUPPORT HAS MOVED OPPOSITE TO SAID ONE DIRECTION SO THAT SAID ESCAPEMENT MEMBER IS FREE TO MOVE TO SAID ENGAGING POSITION EVEN IF SAID OPERATING MEMBER REMAINS IN SAID OPERATIVE POSITION, SAD OPERATING MEANS INCLUDING A MEANS SUPPORTING SAID OPERATING MEMBER FOR MOVEMENT IN SAID ONE DIRECTION, AND RESILIENT MEANS OPPOSING MOVEMENT OF SAID OPERATING MEMBEER WHEREBY SAID OPERATING MEMBER MOVES WITH SAID CARRIAGE MEANS, SAID SUPPORT, AND SAID ESCAPEMENT MEMBER WHEN LOCATED IN SAID RECESS AND ENGAGED BY SAID ESCAPEMENT MEMBER; AND STOP MEANS FOR LIMITING MOVEMENT OF SAID SUPPORT AND SAID CARRIAGE MEANS IN SAID ONE DIRECTION. 